Figure 4.

HDX‐MS reveals a novel functional state in protein kinase A ternary complex. Hydrolysis of cAMP by the protein kinase A (PKA) and phosphodiesterase (PDE) ternary complex was monitored in real time by HDX‐MS. A highly broad mass envelope appeared over time in the ternary complex (top right spectra). Analysis of each component and their possible assemblies (spectra shown on the right) could not explain the distribution seen in the ternary complex indicating this is a unique and catalytically active structural state. Source: Adapted from Reference 54 with permission